Modulators of the Nrf2 Signaling Pathway Enhance the Cytotoxic Effect of Standard Chemotherapeutic Drugs on Organoids of Metastatic Colorectal Cancer.

The activity of known modulators of the Nrf2 signaling pathway (bardoxolone and brusatol) was studied on cultures of tumor organoids of metastatic colorectal cancer previously obtained from three patients. The effect of modulators was studied both as monotherapy and in combination with standard chemotherapy drugs used to treat colorectal cancer. The Nrf2 inhibitor brusatol and the Nrf2 activator bardoxolone have antitumor activity. Moreover, bardoxolone and brusatol also significantly enhance the effect of the chemotherapy drugs 5-fluorouracil, oxaliplatin, and irinotecan metabolite SN-38. Thus, bardoxolone and brusatol can be considered promising candidates for further preclinical and clinical studies in the treatment of colorectal cancer.

Assessing the Efficacy of Anti-Cancer Drugs on Organoid Models Derived from Prostate Cancer.

It was proven that tumor organoids effectively mirror the phenotypic and genetic traits of the original biomaterial. It was reported that outcomes from drug testing in organoid cultures can accurately represent the clinical response observed in patients. In this study, an organoid culture was derived from biopsy material of prostate cancer (PC). Subsequently, clinical practice drugs, docetaxel and enzalutamide, were tested on this organoid culture. Various techniques for evaluating the efficacy of drugs in vitro were compared. The half-maximal inhibitory concentration of docetaxel was found to be markedly lower compared to that of enzalutamide. However, when tested at clinically relevant concentrations and incubation times, enzalutamide was more effective than docetaxel. Therefore, it is crucial to optimize the testing conditions for drugs on in vitro cultures for their subsequent application in clinical practice.

Differences in Presentation of SARS-CoV-2 Omicron Strain Variant BA.1-BA.5 Peptides by HLA Molecules.

In this work, we analyzed the binding affinities of mutated peptides of Omicron strain variants BA.1-BA.5 and the worldwide prevalent HLA alleles. Bioinformatics analysis was conducted with the use of T-CoV web portal. We showed that, for all five viral variants, mutations cause a significant reduction in the number of tightly binding peptides for HLA-B*07:02 and HLA-C*01:02 molecules. At the same time, there were novel potential mutant epitopes (binding affinity less than 50 nM) in case of HLA-A*32:01 allele. Interestingly, mutations caused multidirectional effect on the binding affinities of the viral peptides and HLA-DRB1*03:01. Specifically, Spike protein mutations in the BA.1 variant caused more than 100-fold decrease in PINLVRDLPQGFSAL binding affinity, 10-fold decrease in affinity in the case of BA.2, BA.4, and BA.5 variants, and 30% increase in affinity for the BA.3 variant.

Chemical Induction of Trophoblast Hypoxia by Cobalt Chloride Leads to Increased Expression of DDIT3.

Choriocarcinoma cells BeWo b30 are used to model human placental trophoblast hypoxia using cobalt (II) chloride and hydroxyquinoline derivative (HD) as chemical inducers of hypoxia-inducible factor (HIF). In this study, it was shown that both substances activate the hypoxic pathway and the epithelial-mesenchymal transition and inhibit the pathways of cell proliferation. However, CoCl2 caused activation of the apoptosis pathway, increased the activity of effector caspases 3 and 7, and increased the expression of the unfolded protein response target DDIT3. The mTORC1 pathway was activated upon exposition to CoCl2, while HD suppressed this pathway, as it happens during real trophoblast hypoxia. Thus, effect of CoCl2 on BeWo cells can be a model of severe hypoxia with activation of apoptosis, while HD mimics moderate hypoxia.

Oxyquinoline-Dependent Changes in Claudin-Encoding Genes Contribute to Impairment of the Barrier Function of the Trophoblast Monolayer.

Natural response to hypoxia critically depends on rapid stabilization of hypoxia-inducible factor (HIF). Under normoxic conditions, HIF-prolyl hydroxylases mark α-subunits of HIF for degradation, while hypoxia results in stabilization of HIF-α. Oxyquinoline derivatives suppress activity of HIF-prolyl hydroxylases leading to HIF activation in the cell. Here we show that 24-h incubation of BeWo b30 choriocarcinoma cells (a model of trophoblast in the placental barrier) with oxyquinoline derivative leads to a decrease in transepithelial electrical resistance (TEER) of the cell monolayer, while the permeability of the monolayer for FITC-dextran (70 kDa) remains unchanged. These findings suggest that the overall barrier function is preserved, while the structure of intercellular tight junctions can undergo minor changes. Using Affymetrix Human Transcriptome Array 2.0, we showed that the treatment with oxyquinoline derivative was followed by a decrease in the expression of claudins 6 and 7 (CLDN6, CLDN7), occludin (OCLN), contact adhesion molecule 3 (JAM3), and angiomotinlike protein 1 (AMOTL1).

Metabolic Reprogramming of Trophoblast Cells in Response to Hypoxia.

Hypoxia of trophoblast cells is an important regulator of normal development of the placenta. However, some pathological states associated with hypoxia, e.g. preeclampsia, impair the functions of placental cells. Oxyquinoline derivative inhibits HIF-prolyl hydroxylase by stabilizing HIF-1 transcription complex, thus modeling cell response to hypoxia. In human choriocarcinoma cells BeWo b30 (trophoblast model), oxyquinoline increased the expression of a core hypoxia response genes along with up-regulation of NOS3, PDK1, and BNIP3 genes and down-regulation of the PPARGC1B gene. These changes in the expression profile attest to activation of the metabolic cell reprogramming mechanisms aimed at reducing oxygen consumption by enabling the switch from aerobic to anaerobic glucose metabolism and the respective decrease in number of mitochondria. The possibility of practical use of the therapeutic properties of oxyquinoline derivatives is discussed.

Structure-activity relationship for branched oxyquinoline HIF activators: Effect of modifications to phenylacetamide "tail".

HIF prolyl hydroxylase is a major regulator of HIF stability. Branched tail oxyquinolines have been identified as specific inhibitors of HIF prolyl hydroxylase and recently demonstrated clear benefits in various scenarios of neuronal failure. The structural optimization for branched tail oxyquinolines containing an acetamide bond has been performed in the present study using HIF1 ODD-luc reporter assay. The special attention has been paid to the length of a linker between acetamide group and phenyl ring, as well as substitutions in the phenyl ring in the other branch of the tail. The optimized version of branched tail oxyquinolines is 3-fold more potent than the original one identified before and shows a submicromolar EC50 in the reporter assay. The compounds have been studied in a "liver-on-a-chip" device to question their hepatotoxicity towards differentiated human HepaRG "hepatocytes": the absence of hepatotoxicity is observed up to 200 µM concentrations for all studied derivatives of branched tail oxyquinolines.

mRNA expression profile of mouse oligodendrocytes in inflammatory conditions.

In this study, we performed transcriptome profiling of oligodendrocyte culture of mice treated with the remyelinating therapeutic agent benztropine in the presence and absence of interferon gamma (IFNγ). The results of this work are important for understanding the expression profile of oligodendrocytes under conditions of systemic inflammation in the central nervous system in multiple sclerosis as well as the mechanisms of cellular response to benztropine in light of its possible use for the treatment of multiple sclerosis.

Interference in transcription of overexpressed genes by promoter-proximal downstream sequences.

Despite a high sequence homology among four human RNAi-effectors Argonaute proteins and their coding sequences, the efficiency of ectopic overexpression of AGO3 and AGO4 coding sequences in human cells is greatly reduced as compared to AGO1 and AGO2. While investigating this phenomenon, we documented the existence of previously uncharacterized mechanism of gene expression regulation, which is manifested in greatly varying basal transcription levels from the RNApolII promoters depending on the promoter-proximal downstream sequences. Specifically, we show that distinct overexpression of Argonaute coding sequences cannot be explained by mRNA degradation in the cytoplasm or nucleus, and exhibits on transcriptional level. Furthermore, the first 1000-2000 nt located immediately downstream the promoter had the most critical influence on ectopic gene overexpression. The transcription inhibiting effect, associated with those downstream sequences, subsided with increasing distance to the promoter and positively correlated with promoter strength. We hypothesize that the same mechanism, which we named promoter proximal inhibition (PPI), could generally contribute to basal transcription levels of genes, and could be mainly responsible for the essence of difficult-to-express recombinant proteins. Finally, our data reveal that expression of recombinant proteins in human cells can be greatly enhanced by using more permissive promoter adjacent downstream sequences.

Circulating microRNAs.

The detection of miRNAs in plasma and other body fluids opened up a fascinating possibility that animal noncoding RNAs can act as extracellular signaling molecules. In this review, we discuss recent progress in the field including the ability of miRNAs to participate in intercellular communication in vitro and in vivo, and the application of circulating miRNAs as diagnostic markers of a wide range of diseases. Special attention is paid to the relevance of the development and unification of current techniques for isolation of circulating miRNAs.

Highly informative marker sets consisting of genes with low individual degree of differential expression.

Genes with significant differential expression are traditionally used to reveal the genetic background underlying phenotypic differences between cancer cells. We hypothesized that informative marker sets can be obtained by combining genes with a relatively low degree of individual differential expression. We developed a method for construction of highly informative gene combinations aimed at the maximization of the cumulative informative power and identified sets of 2-5 genes efficiently predicting recurrence for ER-positive breast cancer patients. The gene combinations constructed on the basis of microarray data were successfully applied to data acquired by RNA-seq. The developed method provides the basis for the generation of highly efficient prognostic and predictive gene signatures for cancer and other diseases. The identified gene sets can potentially reveal novel essential segments of gene interaction networks and pathways implied in cancer progression.

Serum metabolic profiles of pregnant women with burdened obstetrical history.

The content of low-molecular-weight components in blood serum was studied by tandem mass-spectrometry in pregnant women. Serum metabolic profiles of patients with a grave obstetrical history were detected. The most significant changes were observed for the concentrations of low-molecular-weight substances involved in glucogenesis and ß-oxidation processes and in metabolic chains involving carbohydrates, carnitines, amino acids, and lipids.

New functions of small nucleolar RNAs.

Small nucleolar RNAs (snoRNAs) are one of the most abundant and well-studied groups of non-coding RNAs. snoRNAs are mostly engaged in processing of rRNA. However, recent data indicate that snoRNAs are also involved in other processes including regulation of alternative splicing, translation and oxidative stress. snoRNAs are also involved in pathogenesis of some hereditary diseases and cancer. Therefore, the range of snoRNAs' functions is significantly wider than it has been assumed earlier.

Circulating miRNAs: cell-cell communication function?

Nuclease resistant extracellular miRNAs have been found in all known biological fluids. The biological function of extracellular miRNAs remains questionable; however, strong evidence suggests that these miRNAs can be more than just byproducts of cellular activity. Some extracellular miRNA species might carry cell-cell signaling function during various physiological and pathological processes. In this review, we discuss the state-of-the-art in the field of intercellular miRNA transport and highlight current theories regarding the origin and the biological function of extracellular miRNAs.

Association of SLC6A4 gene 5-HTTLPR polymorphism with parameters of simple and complex reaction times and critical flicker frequency threshold in athletes during exhaustive exercise.

The incidence of SLC6A4 gene 5HTTLPR polymorphism alleles was evaluated in 223 male athletes engaged in endurance sports, the results were compared with those in 177 male nonathletes. Association between 5-HTTLPR genotypes and the effect of exhaustive treadmill running on simple and complex visual reactions and critical flicker frequency threshold was studied. We found that the incidence of LL genotype was significantly higher in athletes in comparison to nonathletes; after exercise, the velocity of visual reactions and critical flicker frequency increased; exercise did not change the velocity of complex visual reaction in LL-carriers, and increased it in SS-carriers. We conclude that exhausting treadmill running leads to facilitation sensory information processing in athletes and that SS-carriers are more susceptible to the effect of exhaustive treadmill running than LL-carriers.

Changes in parameters of laser-induced potentials after transcutaneous electroneurostimulation.

Changes in nerve conduction after 10-min electroneurostimulation of the posterior surface of the neck were studied. Changes in the parameters of laser-induced potentials obtained during stimulation of C7 dermatome on hands and posterior surface of the neck were found. Decrease in the amplitude and shortening of the component latency were shown. Method of laser-induced potentials was concluded to provide unbiased estimation of the level and peculiarities of analgesic effects of physical factors.

Relationship between lactate concentrations in active muscle sweat and whole blood.

Lactate (lactic acid) concentrations in sweat and venous and capillary blood of athletes were measured before and after exercise of the maximum aerobic power. Correlations between the increment of blood and sweat lactate concentrations were found. Lactate concentrations in the sweat can be used for evaluation of changes in blood lactate levels.

Short highly intense exercise causes changes in salivary concentrations of hydrocortisone and secretory IgA.

The dynamics of salivary hydrocortisone during exercise depends on the professional status of the athlete. Hydrocortisone concentrations increase and those of secretory IgA decrease significantly during short-term highly intense exercise. Presumably, basal serum hydrocortisone level is the key factor in restoration of the secretory IgA concentration after exercise by inhibition of lymphocyte, macrophage, and monocyte functions through an increase in glucocorticoid level under the effect of physiological stressors.